Field of the Invention
The present disclosure relates to a developing roller, a process cartridge and an electrophotographic image forming apparatus.
Description of the Related Art
In electrophotographic image forming apparatuses, a developing apparatus usually includes members for electrography such as the following (1) to (3):
(1) a developer feed roller which resides in a developer container and feeds toner to a developing roller;
(2) a developer amount regulating member which forms a toner layer on the developing roller and keeps a fixed amount of toner on the developing roller; and
(3) the developing roller which covers the opening of the developer container that accommodates toner, while exposing a portion of the developing roller to the outside of the container, in which the exposed portion is disposed to face a photosensitive member to develop the toner on the photosensitive member.
In order to improve the toner conveying ability of a developing member, Japanese Patent Application Laid-Open No. H8-286497 discloses a developing roller in which the surface of an electro-conductive portion is provided with a dielectric portion having a high electric resistance value, and toner can be electrically adsorbed onto the charged dielectric portion to convey the toner.